• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.8
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• pp.673-682
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• 2007

Recently the trend of automobile industry is that IQS evaluation index against a sensitivity quality is increasing. To reduce rattle noise due to speaker sound at low frequencies, it is required the advanced technology analysis process of body structure. This paper optimized the design parameters of package tray panel according to the theoretical background about robust design and suggested the design guideline for resonance avoidance and the reduction of vibrational sensitivity considering the excitation frequency of woofer speaker. And this paper described the design process of a door module panel through the sensitivity analysis in case of the door speaker excitation. Finally, the analysis of the quality deviation using mother car is suggested to guarantee the stable characteristics of vehicle vibration in the early stage of vehicle development. These improvements can lead to shortening the time needed to develop better vehicles.

• Journal of the Korean Home Economics Association
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• v.39 no.11
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• pp.1-14
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• 2001

In order to develop a manual of residential alterations for the physically disabled, this case study was accomplished to analyze and evaluate residential environments and residential alterations for physically disabled women. Twenty-nine physically disabled women in Seoul and Kyunggi areas were the subjects of this study. With the evaluation checklist on physical environments of their housing, data on general characteristics of wall, floor, and all features and equipments and spaces of bedroom, kitchen, bathroom, living mom, entrance and balcony were gathered. Also, data on residential alterations were gathered through personal interviews. The data were collected from July 18th to July 25th in 2000. Frequency, percentage, and mean were used to analyze the data. In kitchen, small space, hee space under the sink and heights of the lower cabinets were not properly provided. In bathroom, door width, direction of opening door, adjustable height of shower, level difference, clear space for wheelchair user, and storage place were not appropriate to the disabled. Kitchen and bathroom showed high frequencies of alteration. But most of the subjects were not satisfied with the alterations of their housing. They also wanted to alter these two spaces in the future. In order to after their housing effectively appropriate information of the residential alterations was needed. If a guide or manual book for residential alterations was provided, the physically disabled people will more easily after their housing for safe and independent life.

• Journal of the Korean Society for Railway
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• v.10 no.3 s.40
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• pp.290-295
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• 2007

The Seoul Metropolitan Subway Corp. have gradually installed screen doors in platforms of 115 subway stations in Seoul on lines 1, 2, 3, and 4. Installation in nine areas among those has been completed and screen doors are being operated as a model operation. Traffic signs should be clear for users. The essential functions of signs should be fully investigated from the aspect of user as well as the visual beauty and recognition. Signs should be able to provide users with information regarding location, position, directions, etc. Particularly, safety and convenient signs should be visually and sensually correlated. However, the entire screen doors in platforms installed in line 2 subway in Seoul are used for commercial advertisement, consequently, the functions and roles as public signs are not fulfilled aggravating inconvenience for users. In this study, cases have been studied to investigate requirements for user-oriented sign system in platform and public sign space to fulfill the functions of sign system in platform. Using an anthropometry approach, the study aimed to obtain the space to install the sign system and to systemize necessary and sufficient conditions for user-oriented system for platform in which screen doors have been installed using. The study suggests fundamental information to obtain the space of public sign system on the entire screen door.

• Journal of Korea Multimedia Society
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• v.25 no.10
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• pp.1416-1432
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• 2022

The access control system is a system that allows users to selectively enter the building by granting an access key to the user for security. Access keys with weak security are easily exposed to attackers and cannot properly perform the role that authenticates users. Access code keys should be protected from forgery or spoofing. For this reason, access key verification service models is important in security. However, most models manage all access keys on one central server. This method not only interrupts all services due to server errors, but also risks forgery and spoofing in the process of transmitting access keys. Therefore, blockchain algorithms are used to reduce this risk. This paper proposes a blockchain-based access key verification service model that used distributed stored blockchain gateways on storing access keys and authenticates the user's identity based on them. To evaluate the performance of this model, an experiment was conducted to confirm the performance of the access key forgery recovery rate and the blockchain network performance. As a result, the proposed method is 100% forgery recovery rate, and the registration and verification process is evaluated at 387.58 TPS and 136.66 TPS.

• Journal of Distribution Science
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• v.20 no.6
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• pp.11-19
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• 2022

Purpose: This study aims at exploring and understanding the effect of four independent variables related to dairy retail marketing and distribution (deep freezers, promotions, company support and distributor-retailer relationship) and one moderating variable Covid-19 lockdown on sales of dairy product during the Covid 19 pandemic situation. Research design and methodology: Personal interviews and door-to-door surveys and promotional tools were designed to publicise and collect data from the retailers. The sale data before, during and after promotion activity were all recorded and evaluated to draw an inferential conclusion. Factor analysis and multiple regression methods were adopted to analyses the data collected. Results: The research shows that four out of the five factors studied was found having significant impact on dairy retail sales. The highest impact on sales was contributed by promotions, secondly by the deep freezer impact followed by distributor-retailer relationship during the study period and lastly but not the least due to influence of Covid-19 lockdown. Conclusions: The study contributes to the body of knowledge in cold chain distribution process through utilization of right mix of tools and tactics for effective marketing and distribution of dairy products in developing countries especially during a pandemic situation.

• Journal of Mechanical Science and Technology
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• v.16 no.11
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• pp.1485-1496
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• 2002

In order to investigate the fire-induced smoke movement in a three-dimensional room with an open door, numerical and experimental study was performed. The center, wall, and corner fire plumes for various sized fires were studied experimentally in a rectangular pool fire using methanol as a fuel. The numerical results from a self-developed SMEP (Smoke Movement Estimating Program) field model were compared with experimental results obtained in this and from literature. Comparisons of SMEP and experimental results have shown reasonable agreement. As the fire strength became larger for the center fires, the air mass flow rate in the door, average hot layer temperature, flame angle and mean flame height were observed to increase but the doorway-neutral-planeheight and the steady-state time were observed to decrease. Also as the wall effect became larger in room fires, the hot layer temperature, mean flame height, doorway-neutral-planeheight and steady-state time were observed to increase. In the egress point of view considering the smoke filling time and the early spread of plume in the room space, the results of the center fire appeared to be more dangerous as compared with the wall and the corner fire. Thus it is necessary to consider the wall effect as an important factor in designing efficient fire protection systems.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1615-1622
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• 2010

Recently, there has been an increase in interest from the aspects of transshipment and connection between the means of transportation. Not only for passengers but also for freight transportation as the need for transportation efficiency is growing while the importance of logistic railway transportation is emerging. The domestic freight transportation is carried out by roads, railroads, ships, and port. However, as other means of transportation, except road, is impossible for Door to Door Service, multimodal transportation accompanied by road transportation is carried out. Here, even though 'transshipment' occurs, because of the lack of basic data regarding this, it is difficult to reflect it in the demand forecasting. With respect to the Korean freight O-D, it was very difficult to have equivalent comparison on the competitiveness and availability of transportation services between the point of departure and the final destination. Taking into account the study of implementation of logit model considering the time and cost of transshipment of multimodal transportation and the transshipment resistance value upon selecting means of freight transportation on multimodal transportation was comparatively insufficient. This study consisted of questionnaire targeting shippers, and based on this, transshipment resistance value was calculated by deriving utility function. By doing so, I intend to examine the effect 'transshipment' has on selecting the means of transportation occurring from freight transportation.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.4
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• pp.477-491
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• 2015

This study analyzes Chinese dresses featured in propaganda posters since the mid-$20^{th}$ century as well as explores the political characteristics of dress. This study used an in-depth interview method to investigate information from 10 Chinese familiar with public awareness and donning practices of the Chinese from 1949 to present. Interviews and analysis provided the following conclusions. First, Zhongshan-zhuang, Liening-Zhuang and Bulaji were widely worn in the Reconstruction because of the revolutionary spirit; in addition, Huayishang also became simultaneously popular as a means to reflect the new aspects of socialism. Second, Jufu/Junbianfu were the most common dresses during the period of Cultural Revolution because the government used various mechanisms to control public opinion. Third, Western fashion began to enter the Chinese market and suit wearing by the Chinese became a symbol of the Reformation and Open-door policy. Traditional dress is no longer a symbol of Feudalism and is a part of Chinese culture that has been reaccepted in the Reformation and Open-door times. Finally, during these 60 years, Chinese dress has obvious political characteristics, but began to change. The changes of political characteristics were, de-politicization expressed by the introduction of Western ready-made, permissions for traditional dress and diversification/ individualization.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.9 s.186
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• pp.134-141
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• 2006

Surface deflections have a great effect on the external appearance of automobiles. Usually, they are occurred on large flat panels containing sudden shape changes and of very small size about $\pm$30$\sim$300$\mu$m. Since the current numerical method is not sufficient for predicting these defects, the correction of these defects still depends on trial and error, which requires a great deal of time and expense. Consequently, developing the numerical method to predict and prevent these defects is very important far improving cosmetic surface qualities. In this study, an evaluation system that can analyze surface deflections using numerical simulation and a visualization system are reported. To calculate the surface deflections numerically, robust algorithms and simulation methodologies are suggested and to visualize them quantitatively, the curvature variation algorithm is proposed. To verify the developed systems, the experimental die of the handle portion of exterior door is analyzed. The results showed that the experimental and simulational visualization are in good agreement. Compensation methods to correct the surface deflections are also tested. The evaluation system proposed in this paper could be used to predict and minimize the occurrence of surface deflections in die manufacturing.

• Solar Energy
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• v.15 no.3
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• pp.119-125
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• 1995

Since the using of heating energy associated with infiltration is significant in a building, the efforts to minimize the infiltration while ensuring minimum ventilation rates for various types of occupancy will be beneficial. In constrast to that many efforts have been made to reduce heat loss by improving thermal resistance of building envelope, little has been tried to reduce heat loss from infiltration. For achieving such an objective, measurement of air leakage rate will be pre-requisite as a diagnostic tool. A blower door system, a depressurization/pressurization method, was employed and it demonstrated a good potential for measuring airtightness performance of residential buildings. Based on the test results, annual energy savings for residential heating was estimated by reducing infiltration to a level of reasonably airtight or to a level of ASHRAE Standard 62-1989 for minimum ventilation.